pregnancy

Table of Contents

Introduction
The normal events of pregnancy
- Initiation of pregnancy
- Diagnosis of pregnancy
  - Symptoms and signs; biological tests
  - Conditions that may be mistaken for pregnancy
  - Duration of pregnancy
- Anatomic and physiologic changes of normal pregnancy
  - Changes in organs and tissues directly associated with childbearing
    - Ovaries
    - The uterus and the development of the placenta
    - Uterine tubes
    - Vagina
    - External genital structures
    - Other pelvic tissues
    - Breasts
  - Anatomic and physiologic changes in other organs and tissues
    - Cardiovascular and lymphatic systems
    - Respiratory tract
    - Gastrointestinal tract
    - Liver
    - Urinary tract
    - Blood
    - Endocrine system
    - Skin
  - Metabolic changes
    - The basal metabolic rate
    - Weight
    - Protein
    - Carbohydrates
    - Fat
    - Water
    - Minerals
- Prenatal care and testing
  - Ultrasound
  - Amniocentesis
  - Chorionic villi sampling
  - Alpha-fetoprotein screening
Abnormal changes in pregnancy
- Ectopic pregnancy
- Abortion
- Systemic diseases and pregnancy
  - Heart disease
  - Endocrine diseases
    - Diabetes
    - Thyroid disease
    - Pituitary disorders
    - Adrenal glands
  - Urinary tract diseases
  - Pulmonary disease
  - Gastrointestinal diseases
  - Nervous system disorders
- Diseases of pregnancy
  - Hypertensive disorders of pregnancy
  - Gestational diabetes
  - Diseases of the placenta
    - Placenta praevia
    - Abruptio placentae
    - Placental infarction
    - Placenta accreta
    - Placental cysts and benign tumours
    - Inflammation of the placenta
    - Placental anomalies
  - Anomalies of the umbilical cord
  - Abnormalities of the amniotic fluid
    - Hydramnios
    - Oligohydramnios
  - Trophoblastic disease
    - Hydatidiform mole
    - Choriocarcinoma

References & Edit History Related Topics

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Learn how researchers use biobanks, such as the Improved Pregnancy Outcomes by Early Detection study, or IMPROvED to improve maternal and newborn outcomes

initiation of pregnancy; fertilization and implantation

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pregnancy summary

pregnancy

Written by John W. Huffman

Fact-checked by The Editors of Encyclopaedia Britannica

Last Updated: Jan 7, 2025 • Article History

Related Topics:: reproductive system disease; high-risk pregnancy; ectopic pregnancy; maternal imagination; maternal mortality

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pregnancy, process and series of changes that take place in a woman’s organs and tissues as a result of a developing fetus. The entire process from fertilization to birth takes an average of 266–270 days, or about nine months. (For pregnancies other than those in humans, see gestation.) A new individual is created when the elements of a potent sperm merge with those of a fertile ovum, or egg. Before this union both the spermatozoon (sperm) and the ovum have migrated for considerable distances in order to achieve their union. A number of actively motile spermatozoa are deposited in the ...(100 of 19882 words)

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